抄録
The class of faster firing neurons in the superior central raphe (CES) was examined in freely behaving rats, during various motor movements as well as SWS and PS. These non- serotonergic raphe neurons fired slowly during SWS (5.9/s ; mean) and immobility or quiet waking (7.5/s), more frequently during PS (12.8/s), and the most frequently during other various motor behaviors (16.6/s). The CES units tended to fire in bursts during the “twitch periods” of PS, i. e., a kind of movement phase of PS. During various movements, two major types of firing were observed. Type A units had a significantly higher firing rate during Type I behaviors than Type II behaviors according to Vanderwolf's classification. Type B units showed no difference in the firing rate between the two types of behaviors, but, for both types of behaviors, Type B units had a higher firing rate during vigorous movements. These two types of CES neurons equally had a few to several neural discharges in burst firing at the onset of behaviors. The present results suggest a possibility that the faster firing CES neurons may play a role in initiation of behaviors.
